Compound silicon-free long nozzle and manufacturing method thereof

Abstract

The invention discloses a compound silicon-free long nozzle and a manufacturing method thereof. The compound silicon-free long nozzle comprises an outer-layer body which comprises 15 to 35 weight percent of crystalline flake graphite, 35 to 55 weight percent of white corundum, 20 to 50 weight percent of aluminum titanate, and 8 to 10 weight percent of externally added plaenolic resin binder, and an inner layer which comprises 60 to 90 weight percent of aluminum titanate, 10 to 40 weight percent of corundum, and 3 to 5 percent of externally added alumina gel bonding agent. The compound silicon-free long nozzle consists of an alumina-carbon outer layer and a carbon-free inner layer, and in the carbon-containing outer layer, silicon carbide and fused quartz in an alumina-carbon nozzle are replaced by aluminum titanate, so a product does not have silicon; and the carbon-free inner layer consists of aluminum titanate and corundum, so the inner layer does not have carbon, and the compound silicon-free long nozzle is used for production of clean steel.

Description

technical field [0001] The invention relates to a nozzle and a manufacturing method, in particular to a composite silicon-free shroud shroud used in continuous steel casting production and a manufacturing method thereof. Background technique [0002] When the continuous casting molten steel is poured from the ladle to the tundish, in order to avoid secondary oxidation and splashing, a long nozzle is installed at the lower end of the sliding nozzle at the bottom of the ladle, one end is connected to the lower nozzle, and the other end is inserted into the molten steel in the tundish for sealing protection pouring. [0003] The functions of the long nozzle are as follows: (1) prevent the secondary oxidation of molten steel and improve the quality of the steel; (2) reduce the deposition of oxidation products of easily oxidized elements in the steel on the inner wall of the nozzle and prolong its service life; (3) the long nozzle can be used multiple times Use to reduce refract...

AI Technical Summary

Problems solved by technology

[0007] The object of the present invention is to provide a composite silicon-free long nozzle and its manufacturing method, which is composed of an aluminum-carbon outer layer and a carbon-free inner layer. The carbon-containing outer layer uses aluminum titanate to replace silicon carbide and fused quartz in a traditional aluminum-carbon nozzle. To make the product non-silicified, the use of aluminum titanate material modified by the binder overcomes the disadvantage of low strength of the sintered body of aluminum titanate material, which not only ensures the mechanical strength of the nozzle and good thermal shock resistance, but also prevents the Traditional Al 2 o 3 - SiO in the long nozzle of C quality 2 Reaction with MnO or FeO in molten steel to generate low-melting-point substances causes the defects of reduced corrosion resistance and erosion resistance of the nozzle; the carbon-free inner layer of the composite silicon-free long nozzle provided by the present invention is composed of aluminum titanate and corundum, realizing no Carbonization, prevents the formation of CO and thus leads to Al 2 o 3 The formation and attachment of the nozzle ensure the smoothness of the inner wall of the nozzle, which is conducive to the purity of molten steel, and can be used for the production of pure steel

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